1. Field of the Invention
The present invention generally relates to a vehicle on-board unit. More specifically, the present invention relates to a host vehicle having a vehicle on-board unit that outputs a brake light activation signal without performing a braking operation in the host vehicle upon detecting a vehicle traveling condition indicative of a potentially inadequate safety zone occurring in the host vehicle.
2. Background Information
Recently, vehicles are being equipped with a variety of informational systems such as navigation systems, Sirius and XM satellite radio systems, two-way satellite services, built-in cell phones, DVD players and the like. These systems are sometimes interconnected for increased functionality. Various informational systems have been proposed that use wireless communications between vehicles and between infrastructures, such as roadside units. These wireless communications have a wide range of applications ranging from crash avoidance to entertainment systems. The type of wireless communications to be used depends on the particular application. Some examples of wireless technologies that are currently available include digital cellular systems, Bluetooth systems, wireless LAN systems and dedicated short range communications (DSRC) systems.
Dedicated short range communications (DSRC) is an emerging technology that has been recently investigated for suitability in vehicles for a wide range of applications. DSRC technology will allow vehicles to communicate directly with other vehicles and with roadside units to exchange a wide range of information. In the United States, DSRC technology will use a high frequency radio transmission (5.9 GHz) that offers the potential to effectively support wireless data communications between vehicles, and between vehicles, roadside units and other infrastructure. The important feature of DSRC technology is that the latency time between communications is very low compared to most other technologies that are currently available. Another important feature of DSRC technology is the capability of conducting both point-to-point wireless communications and broadcast wireless messages in a limited broadcast area.
Accordingly, wireless technology can be used to provide various information from vehicle-to/from-infrastructure, and from vehicle-to-vehicle, such as providing GPS location, vehicle speed and other vehicle Parameter Identifiers (PIDs) including engine speed, engine run time, engine coolant temperature, barometric pressure, etc. When communications are established with between vehicles and/or roadside units in close proximity, this information would be communicated to provide a complete understanding of the vehicles in the broadcast area. This information then can be used by the vehicles for both vehicle safety applications and non-safety applications.
Recently, a Vehicle Safety Communication Consortium (VSCC) was established to study safety applications of wireless communications. The Vehicle Safety Communication Consortium developed a list of safety applications that were believed to have the highest potential for reducing the number or mitigating crashes. During these studies, one particular application that was developed was called the Emergency Electronic Brake Light application (EEBL). In the Emergency Electronic Brake Light application, a vehicle-to-vehicle communication is established with an aim to prevent rear end crashes by communicating a hard braking event by a preceding vehicle to other vehicles in the vicinity. In this application, a vehicle can be notified of the hard braking event even if the driver cannot see the brake lights of the preceding vehicle, e.g. when a truck or a terrain obstacle is blocking the driver's view of the brake lights of the preceding vehicle. However, the so called the Emergency Electronic Brake Light application only provides information to following vehicles after the brakes have been applied. This application does not aid in maintaining a safe distance between the host vehicle and a following vehicle.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved vehicle on-board unit. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.